Shingle material and method of manufacture



Patented Jan. 8, 1929.

srATEs PATENT OFFICE.

ALBERT L. CLAPP, or mmvnns, MASSACHUSETTS, assrenora To THE rnin'rxo'rncom:- PANY, or BOSTON, MASSACHUSETTS, A CORPORATION or MASSACHUSETTS.

SHINGLE MATERIAL AND METHQD OF-MANUFACTUBE.

No Drawing.

ren'iaiuing fiat under all weather conditions,

and which may be completely formed on a paper machine, withoutsubsequent saturating or coating processes.

Much trouble has been experienced with shingles formed of the so-calledasphalt roofing, which is commonly composed of rag felt saturated withasphalt and then provided with a suitable surface layer such as acoating -of high melting point or blown asphalt, and an exposed fac ngof granular material such as crushed slate thereto, due to thecurling-or warping of the shingles after they have been laid in positionon the roof. Heretofore it has generally been believed that this curlingand warping is due to faulty saturation of the material permittingexposure of the fibers to the weather to absorband give ofi moisturewith changing atmospheric conditions. Much attention has'therefore beendirected to the problem of insuring as complete saturation as possiblein order to seal the fibers against exposure to the atmosphere.considerable experimentation I have come to the conclusion thatimperfect saturation plays only a minor part in such Warping andcurling. Irrespective of the amount of saturant commercially employed insuch material,

' I have found that it readily absorbs from 6% to 50% by weight ofmoisture when immersed in water for twenty-four hours. This does notnecessarily mean that the material is not water resistant, but merelythat it is prac tically impossible to prevent capillary ab-v sorption ofwater into the cells of the illdlw vidual fibers irrespective of thethoroughness with which the felt is saturated with waterproofingmaterial.

It is my belief that the cause of the curling.

and warping is chemical change within the more or less hydratedindividual fiber cells, the hydrated cellulose being unstable, theamount of water within the fibers occurring either as chemicallycombined with the cellulose or free and being variable under variableclimatic conditions. l Y

I have found that certain fibers have less tendency to hydrate and toabsorb water than others, and that the fibers which have great capacityfor hydration and absorption of tion than new rags.

From 4 Application filed September 12, 1923. Serial No. 662,225..

waterby the capillary cells also showa strong tendency forthe feltedmaterial made therefrom to warp and curl, when dry, under ch anger; inatmospheric conditions. Arranged in their order as to their capacity ofhydration and cellular capillary absorption, the variouscellulosicfibers in common use may be listed somewhat as follows: (1)rope and sulphate pulp, (2) sulphide pulp, (3) news pulp and (4) rags.That is, a board made from sulphate pulp or rope after being driedcurls'more than one made from sulphite pulp beaten outthe same length oftime, and a board made of sulphite pulp curls more than one made ofnews? pulp or of rags beaten out the samelength of time. It should benoted, however, that there is considerable danger of curling even withthe more inert cellulose fiberssuchas those of rags, in case they arebeaten out hard for a considerable length of'timeso as to becomehydrated. I have. found that old rags have less capability of hydrationand cellular capillary absor This fact I belive to e due to the greaterproportion of oxyhydrocellulose in the old rags, the presence of theoxyhydrocellulose indicatin that the fibrous structure is more or lessbro en down, so that thecapillaries of the individual fibers are lesspronounced than inthe new rags. This condition is doubtless dueto apartial oxidiare free from such warping and curling tendencies. Forexample, asbestos fiber which is inert in respect of hydration, has afreedom from any tendency to curl and warp. Asbestos fiber-alone,however, does'not form combination with water so as to be hydrated andfelt readily on the paper machine and it is therefore desirable, inorder to produce proper felting, to mix it with other fibers,

such for example as rags, which in themselves are the freest of thevarious cellulose mate-1 rials from curling and. warping tendencies.

Smaller-proportions of news, still smaller proportions ofsulphite andyet smaller proportions of sulphate pulp may also beused withoutpermitting the curling and warping tendencies of these latter fiberstoovercome dized and brittle.

little or no tendency to curl.

the inert nature of the asbestos fibers so as .t cause the final productto curl or -warp. When exposed to. the weather for a long period of timethe cellulose fibers of the ordi nary asphalt shin les such as arecommonly made from rag elt saturated and coated withasphalt, becomesoxyhydrated but by that time the asphalt itself has become cm- Theoxyhydration of the cellulose fibers destroys the strength of theshingle and the'useful life of the shingle is thus ended. The asbestosis not subject to this deterioration and thus prolon s the use- 'fullifeof the shingle, especlally s1nce felted asbestos becomes denser with lase of time.

I propose, therefore, to emp oy asbestos fiber or other non-hydratablefiber as the major or" preponderant portion of the fibrous material tobe used, together with sufiicient cellulosicmaterials, preferably of theleast possible hydrating tendencies and beaten as little as possible, toform a fibrous mixture capable of being run off satisfactorily on thepaper machine and, which, when dried, has Also in order to avoid thenecessity of saturating the material so formed in order to render itwaterproof, I propose to incor' orate the waterproofing material in thefi rous pulpy stock so that the sheet as initially formed contains thewaterproofing agent. It might also be stated here that it is 'fiicultto'saturate felted asbestos. Any desirable coloring matter may also beincorporated to give the desirable color to the finished material.

For example, one may proceed as follows: 30 parts of asbestos (longor-short fiber), 15 parts of rags, 15 parts of newspa er and a-sufficient quantity of water are loa ed into a 40.

beaterw together with any suitable coloring matter (which, if desired,may comprise one part Prussian blue) 2-parts red iron oxide, 2 partsivory black, and 1 part nigrosine) and powdered unsaponifiedwaterproofing materials, such as20 parts of montan wax and 20 arts ofgilsonite, and the mixture is hard aten for 2 hours. 5 parts of rosinsize and 5 parts of silicate of soda are then added and mixed in for 20minutes, whereupon 10 parts of aluminum sulphate or other suitableprecipitant are then added and beaten in for 20 minutes to precipitatethe sizeand silicate of soda in the form ofa coagulum which fixes theunsaponified waterproofing materials,- i. e.," the wax, gilsonite, andcoloring matter on the fibers, This pulp is then trans ferred to anysuitable paper makin machine,

e. g. a wet paper machine and w en. of the desired caliper thesheetremoved therefrom in the form of a board. This board is then air dried,the discrete or finely divided particles of thermo-plastic materialfluxed and coalesced by heat and pressure, c'alendered and cut intoshingles.

I have found that asbestos is most desirable in the to the trade asfiber to prevent the shingles from curling or warpin but that anyproportion of sulphate pulp a ove about 30% causes curling and warpingeven though asbestos is used. The

curling properties of cellulosic fibers, for ex- I and aids in'holdingthe waterproofing materials incorporated in the pulp while it is be-.ing run on the paper machine. For example,

.10 asbestos, 30% of wood flour and 10% of rags by weight maybe'successfully used ulp.

In pl as stated'in the example hereinbefore given,

one hundred arts of (wet) as halt emulsion made according to the Kirchraun method and 20 parts of powdered montan wax or ace of the montan waxand gilsonite gilsonite may be used. This asphalt emulsion is made byemulsifying or dispersing a normally adhesive as alt in ,water with acolloidal clay emulsilgyin agent, and is known emulsion. ,For example,the furnish may consist of 50 parts asbestos, 10 parts ra 20 partsmontan wax, arts of wet K emulsion, 1 part ivory blac 5 parts rosinsize,10 parts silicate of soda, and 20 parts aluminum sulphate. The

emulsion alone is too flabby to serve as the entire waterproofingmaterial of a rigid shingle, but by the addition of a hard thermoplasticmaterial such as montan wax or gilsonite, the product is rendered quitestill and rigid. A suitable shingle, however, may be produced by the useof KB emulsion alone as the waterproofing agent. the variouswaterproofing agents above enumerated, leather dissolved in caustic sodamay be used. Forexample, the furnish may comprise 5Q parts of asbestos,30 parts of rags, 100, parts wet KB emulsion, 20 parts of leather, 2parts of caustic soda, and 8 to 10 parts of alum. The asbestos and ragsare beaten up together, and the leather and caustic may be mixedtogether with water to form Together with mixed with the fibers, the KBemulsion is incorporatedin the pulp and then the alum is added. Thisprecipitates the leather in insoluble elatinous' form which fixesthewaterproo ng agent on the fibers.

The stock is then run off on the aper machine and further treated asherein efore described.

, amples hereinbefore given The precipitated leather forms a more orless waterproofing agent which is not subj set to deterioration byoxidation on exposure to the weather. Of course any desired coloringmatter may be added to the furnish to color the final product.

Adverting once more to the use of various forms of fibers which may be"employed in the manufacture of so-called asphalt shingles, it is mybelief'that when cellulose fibers are hydrated, the pulp, the fibers,even after the sheet is dried as ordinarily, contain water of hydration,which is alternately freed and again chemically combined with thecellulose cells, under the conditions to which such shingles aresubjected in use. These chemical changes result in physical changes inthe shingle. which are manifested b warping thereof, this of the coatingor surfacing materials with which such shmgles are ordinarily rovided.Consequently when cellulosic fi ers are pulped with inert fibers, suchas asbestos, the

beating operation shouldbe so carried on as to effect a homogeneousmixture with the least possible hydration of the, cellulose fibers. Asheet formed solely of asbestos does not expand and contract whenexposed to the weather for an indefinite eriod of time and neither curlsnor warps, ut lies fiat. Consequently for the best results onlythat-proportion of cellulosic' material should be mixed with theasbestos in the pulplng operation, as is necessary for the dproperformation and felting of the finishe sheet. The exof various proportions of the components are intended t0 serve only as guides in thepractice of mg invention, as of course the proportions an the particularingredients maybe changed, provided the' principles herein pointed outare borne in mind. It might also be noted that when the non-hydratingfiber used is asbestos the shingle is rendered quite firepgof. 1

While the term shingle .has

used it should be understood that this'is intended to include shingles,shingllp strips and other individual weather-proo formed from sheetmaterial.

Having thus described this invention it will be evident to those skilledin the art that many modifications and changes might be made withoutdeparting from its spirit or scope as defined by the appended claims.

I claim:

1. The method of forming a. shingle-which comprises beating up asbestosfiber, cellulosic fiber and waterproofin then adding precipita lesizingand continuin the beating, then adding a precipitant or the sizing andbeating, running 0 on a paper machine, andthen fluxing, and finallycutting the sheet thus formedinto roofing shingles.

more or less, in the preparation of the curling and ta ing place inspite en herein thermo-plasti'c waterproofin g elements tion of cullumaterial in water,

2. The method of forming a shingle which I comprises beating up asbestosfiber, cellulosic fiber, comminuted cellulosic material, andwaterproofing material in water, ing precipitable sizing and continuingthe beating, then adding a precipitant for the sizing and beating,running off on a wet then add paper machine, and then fluxing andcalendering, and finally cutting the sheet thus formed into roofingshingles. 3. The method of forming a shingle which comprises beating upasbestos fiber, c'ellulose fiber and waterproofing material in water,

then adding recipitable sizing and continuing the beating, then addingaprecipitant for the sizing and beating, running'ofi on a wet papermachine, and then air drying, flux ing and calendering, and finallycutting the sheet thus formedinto roofing shingles. 4. A shinglecomprising a'fibrous foundation having the felted characteristics ofpaper machinefabrication and comprising asbestos,

and bituminous waterproofing material co a-' lesced throughout saidfoundation.

- 5. A shingle comprising a fibrous foundation having'the feltedcharacteristics of paper machine fabrication and consisting of asbestosand cellulosic material,- and bituminous watcrproofin material coalescedthrou hout said foun ation.

6. shingle comprising a fibrous foundation having the feltedcharacteristics of paper maohinefabrication and consisting of asbestosand cellulosic material, the asbestos forming the major portion of saidfoundation, and bituminous waterproofing material coalesced throughoutsaid foundation.

7. A shingle comprising a'fibrous founda- A tion havin the feltedcharacteristics of paper machine abrication and comprising nonhydratingfibrous material, a waterproofing agent, and a waterproofing coagulumpermeating said foundation. Y

8. A shingle comprising'a fibrous founda- 1 ,tion having the feltedcharacteristics of paper machine fabrication and comprisingnon-hydrating fibrous material, and a giagent and coloring matterpermeating sa'i 9. A shingle comprising a fibrous founda fo'undation. v115 tionhaving the felted characteristics of pa er I 'machinefabrication and comprising non.- y- -drating fibrousmateriahand-a thermoplas- 'tic waterproofing agent and coloringmatter grmeating saidfoundationand fixed to the ers.

10. A shingle comprising a fibrous-founda-' osic material and asbestoshavin the felted characteristics of paper ma- "chme fabrication, saidfoundation having hard wax, asphalt emulsion, coloring matter, and awaterproofing coagulum permeatin the foundation and fixed to the fibersthereo 11. A shingle comprising a fibrous foundation of cellulosicmaterial and asbestos on a paper making machine, said fibers comprisinga prcponderating proportion of fibers inert to hydration, together withsufficient cellulosic fibers to permit the felting of the fibrous masson a papermaking machine, and containing a thermo-plastic Waterproofingcompound coalesced in the sheet from finely divided particles thereof.

15. A shingle comprising a fibrous foundation of cellulosic and asbestosfiber filled with comminuted cellulosic material and felted on apapern'iaking machine, saidfoundation being permeated with unsaponifiedthermoplastic waterproofing material fiXed to said fiber by precipitatedwaterproofing material. I

16. A shingle comprising a fibrous foundation of cellulo'sic asbestosfiber, filled with comminuted cellulosic material and felted on apapermaking machine, said foundation being permeated with the coalescedparticles of finely divided asphalt and hard Wax fixed to said fiber byprecipitated leather.

In testimony whereof I have afiixed my signature.

ALBERT L. CLAPP.

